Alarm for pneumatic tires.



CA E. UHNSON, ALARM FOR mmm/mc mais.

APPUCATIOT HLN) MN, 18 1315.

Patented Jun@ 13, 1916.

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CHARLES E. JOHNSON, OF GRAND RAPIDS, MICHIGAN.

ALARM FOR PNEUMATIC TIRES.

Specication of Letters Patent.

Patented J une 13, 1916.

Application filed January 18, 1915. Serial No. 2,908.

To all whom it may concern.'

Be it known that I, CHARLES E. JOHNSON, a citizen of the United Statesof America, residing at Grand Rapids, in the county of Kent and State ofMichigan, have invented certain new and useful Improvements in Alarmsfor Pneumatic. Tires; and I do hereby declare the following to be afull, clear, and exact description ot' the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

This invention relates to an alarm for pneumatic tires. I

The object and purpose of the invention 1s to provide a device of thischaracter which may be attached to the valve stern of a pneumatic tireand used with any tire irrespective of the degree of the pressure towhich it is inflated, the device acting when the pressure of the ti'rcreduces below this initial pressure which it had when the .device wasattached, to sound an alarm, calling attention to the fact of pressurereduction.

It is a further object of the invention to provide an alarm which willact continuously for a time, will lthen stop and later repeat the alarmwith reference to a new pressure iu the air tube.

Further objects and purposes consisting in novel constructions andarrangements of parts to torni a compact, easily manufactured andassembled device will be apparent upon understanding of the embodimentshown in the accompanying drawings, in which; i

.Figure 1 is a side elevation of the alarm. Fig. Q vertical sectiontaken centrally thereof and showing the parts in one position with thealarm not sounding. Fig. 3 is a view similar to Fig. 2 showing theposition of the parts when the alarm Vis sounding. Fig. i is a.sectional View of the whistle used. Fig. 5 is a vertical sectional Viewtaken centrally of a modified construction; and Fig. 6 is a horizontalsection on the line 6-6 of Fig. 5.

Similar reference numerals refer to similar parts throughout the severalviews of the drawing.

A section of an air tube is shown at 1 which carries a valve stem 2secured by means of the nut 3 to the tube and which is equipped with theusual spring operated valve pin Il, the depression of which. permits theescape of air from the air tube. In the embodiment illustrated in Figs.1 toY 3 inelusive, a semi-spherical member 5 equipped with an integralnut 6 is screwed Aonto the valve stem, while a similar member 7 threadson to the casing 5 to complete the housing of the alarm and themechanism lwhich operates it. A tube 8 is formed integrally with orsecurely attached in any suitable manner to the upper part 7 and ispositioned vert-ically,'and`its lower end may lie around the upper partof the valve stem 4. A partition 9 is formed in the tube and providedwith a conical valve seat to receive the conical valve 10 and, at adistance below this valve,'a finger 11 attached to one side of the tubeeX-' tends inwardly at its ,end bearing upon the valve pin 1. `When thehousing is attached to the valve stem the linger depresses pin 4 andpermits the escape of air from the tube.

An opening 12 is made in the'tube 8 below thc partition 9 while abovethis partition the tube is closed by the comparatively thick crossmember 13 in which is threaded a whistle 14, there being an opening 15leading from one side of the member 13 and through the tube 8 to thewhistle. O eings 16 and 17 are made in the' tube 8 be ow the crossmember 13, the opening 16 lying in the same vertical plane with opening15. Also an opening 8a is formed in tube 8 above cross member 13 asshown. 1t will be lnoted that a portion of the upper casing 7 is removedat the end of the tube 8 and that the whistle 14 is located in thisopening.

A sleeve 18 is slidably mounted on the upper half of the tube 8, itsupper end normally covering opening 8, its lower end being connectedwith a diaphragm 19 circular in outline the edges of Which are receivedbetween the members 5 and 7, the diaphragm thus forming an air tightpartition between the upper and lower halves of the housing. Sleeve 18has an opening 20 normally registering with the opening 17 in tube 8andis` furthermore provided with Ya section 21 pressed outwardly to forma passageway betwnthe sleeveb and tube 8 which, as shown in Fig. 2,normally communicates with the upper opening 15 but terminates short ofthe opening 16.

After the tube l has been inflated the device is attached to the valvestem 2 whereupon air is released'from the air tube passing through,opening 12 and filling the lower halt of the housing withv air at apressure equal to that within the tube. The

30 operative when the pressure said tube having two openings thereinpermitting the passage of air, a cross member in the tube above theopenings having a transverse opening therein, a whistle carried by thecross member communicating with the. opening, a sleeve provided with anopening normally in alinement with one of the openings in the tube andwith an outwardly pressed section immediately above the other openingand over the opening in the transverse member slidably mounted on thetube, a member connected to the sleeve dividing the housing into upperand lower air tight compartments and a valve in the tube below theopenings therein. substantially as described.

3. An alarm for pneumatic tires `comprised of a housing, a memberdividing the housing into upper and lower air tight compartments. a tubeextending through the upper compartment, a sleeve slidably mounted onthe tube` a whistle in the tube, means for securing the housing to thevalve stem ot' an air tube, means to release air from the tube into thehousing when it is attached. a valve permitting the passage of air fromthe lower to the upper chamber, but preventing its return, passages forair from the tube through the whistle becoming in the upper compartmentbecomes greater than in they lower compartment moving the sleeve on thetube, and means to reduce the pressure in the upper compartment and stopthe passage of air through the whistle on downvard movement of thesleeve beyond a predetermined point.

4. An alarm for pneumatic tires comprised of a housing adapted to besecured to the valve stem of a pneumatic tire, a movable lnelnberdividing the housing into two compartments. means for connecting onecompartment with the air tube to make the air pressure equal to thepressure in the tube. means` to equalize the pressure in bothcompartments whenever the pressure in the compartment connected with theair tube becomes greater than in the other compartment. and means tosound an alarln for an appreciable length ot' time when the pressure insaid tube connected compartment becomes less than in the othercompartment` substantially as described.

ln testimony whereof l allix my signature in presence ot' two witnesses.

CHARLES li. JOHNSON.

'itnesscs:

'FRANK ll. Ltwzlmxcr., Jr.,

Il. ll. Yamcixu'rox,

